User talk:49.207.50.57

July 2018
Hello, and welcome to Wikipedia. Although everyone is invited to contribute, at least one of your recent edits, such as the one you made to Isotopes of hydrogen, did not appear to be constructive and has been reverted or removed. Please use the sandbox for any test edits you would like to make, and read the welcome page to learn more about contributing constructively to this encyclopedia. Thank you. Double sharp (talk) 06:08, 1 August 2018 (UTC)